The present invention relates generally to network management and, more particularly, to estimation of traffic matrices in a network.
A traffic matrix provides, for every ingress point i into a network and egress point j out of the network, the volume of traffic Ti,j from i to j over a given time interval. The traffic matrix, together with network topology and routing and fault data, can facilitate diagnosis and management of network congestion—as well as provide critical inputs to network design, capacity planning and business planning. Unfortunately, traffic matrices are generally unavailable in large operational Internet Protocol (“IP”) networks. Rather, typical production systems gather data on resource utilization at network nodes and links (e.g. link loads); end-to-end performance metrics for specific transactions (such as one way delay statistics for packets exchanged between measurement servers at the network edge); and status and configuration of network topology and routing. Though these may reveal traffic anomalies or congestion problems, they do not in general reveal potential solutions. For instance, link load measurements may reveal congestion on a link, but shed little light on its cause, which in general requires understanding the traffic matrix.
The inability of network operators to measure the traffic matrix is a fundamental obstacle to developing sounds methods for network and traffic engineering in operational IP networks.